Backlight module device

ABSTRACT

A backlight module for a flat panel display comprises a light guide plate having at least one projecting lug on the peripheral edge of at least one side thereof, said projecting lug being connected to a peripheral edge of the light guide plate with a top front portion thereof and connected to the other peripheral edge on the same side of the light guide plate with a bottom end portion thereof; and a frame which surrounds at least a part of the peripheral edge of the light guide plate and includes an opening to closely receive the projecting lug of the light guide plate; wherein the top front portion of the projecting lug, the bottom end portion of the projecting lug and the tip portion of the projecting lug at the utmost distance from the peripheral edge on the same side of the light guide plate are disposed in a nonlinear manner among themselves.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a backlight module for flatpanel display devices, and more particularly, to a backlight module forliquid crystal display devices (LCDs).

[0003] 2. Description of Related Art

[0004] The backlight module of a LCD device tends to be damaged indelivery or by an inadvertent impact or drop. In this case, for example,the light guide plate of the backlight module impinges on the lightsource such as lamp contained in the backlight module when impact ordrop occurs. As such, the light source (lamp) of the backlight moduleslips down, breaks or cracks so that the duration of use or theproduction yield of the LCD device is decreased. Therefore, to ensurethe quality of the display products, some manufacturers have had theproduct gone through glide tests and impact tests for the LCD device aswell as the backlight module thereof before delivery of the products.However, significant improvement in reducing the impact stress forcesand damage to the backlight module, e.g., crack or breakage of the lightguide plate or the light source, has not yet been provided.

[0005] Therefore, it is desirable to provide an improved backlightmodule to mitigate and/or obviate the aforementioned problems.

SUMMARY OF THE INVENTION

[0006] The primary object of the present invention is to provide abacklight module for a LCD which increases the durability against anyimpact, homogeneously distributes the impact stress forces, reduces theimpact force and reinforces the light guide plate.

[0007] Another object of the present invention is to provide a lightguide plate for a LCD which increases the durability against any impact,homogeneously distributes the impact stress forces, reduces the impactforce and reinforces the light guide plate.

[0008] To achieve the objects, a backlight module for a flat paneldisplay according to the present invention comprises a light guide platehaving at least one projecting lug on the peripheral edge of at leastone side thereof, said projecting lug being connected to a peripheraledge of the light guide plate with a top front portion thereof andconnected to the other peripheral edge on the same side of the lightguide plate with a bottom end portion thereof; and a frame whichsurrounds at least a part of the peripheral edge of the light guideplate and includes an opening to closely receive the projecting lug ofthe light guide plate; wherein the top front portion of the projectinglug, the bottom end portion of the projecting lug and the tip portion ofthe projecting lug at the utmost distance from the peripheral edge onthe same side of the light guide plate are disposed in a nonlinearmanner among themselves.

[0009] Other objects, advantages, and novel features of the inventionwill become more apparent from the following detailed description whentaken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a top view of the backlight module according to thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0011] The position of the projecting lug of the light guide plate ofthe backlight module of the present invention on the light guide plateis not limited, and preferably, the projecting lug of the backlightmodule is mounted on one side of the light guide plate without facinglight source. This means that the projecting lug of the backlight moduleis mounted on the non-directly-facing-light source side of the lightguide plate, that is, any side other than the side directly facing alight source in cooperation with the light guide plate. Preferably, theprojecting lug is disposed on the two non-directly-facing-light sourcesides of the light guide plate or the sides of the light guide platewithout facing light source symmetrically to buffer the impact force ashit. Moreover, at least one side of the light guide plate without facinglight source or the directly-facing-light source side of the light guideplate of the present invention is preferable to have a cave at theperipheral edge of the directly-facing-light source side to adequatelyreceive a lamp holder so as to avoid any crack or breakage of the lampbecause the peripheral edge of the light guide plate smashes into theconjunction, which is the most fragile part of the light source, betweenthe lamp holder (power cable socket) of the light source (the lamp) andthe lamp when hit caused by falling down onto the ground, for example.The front and back portions of the projecting lug of the backlightmodule of the present invention, the peripheral edge of the light guideplate connected to the top front portion of the projecting lug on thelight guide plate side and the other peripheral edge connected to thebottom end portion of the projecting lug on the same side of the lightguide plate are not limited, and preferably, the peripheral edge of thelight guide plate connected to the top front portion of the projectinglug and the other peripheral edge of the light guide plate on the sameside of the light guide plate connected to the bottom end portion of theprojecting lug are arranged in a nonlinear manner such that the contactarea between the light guide plate and its corresponding frame isenlarged and the anti-force of the light guide plate of the backlightmodule on the side longitudinal to the light source is increased. Theshape of the projecting lug of the light guide plate of the backlightmodule of the present invention is not limited, and preferably, theshape of the projecting lug is trapezoid or triangle, and morepreferably, the length of the peripheral edge connected to the top frontportion of the projecting lug is longer than the peripheral edgeconnected to the bottom end portion of the projecting lug. The backlightmodule of the present invention may further comprise an assembly membersuch as optical film, reflecting plate and light source. The backlightmodule of the present invention further comprises a frame which mayenclose in part or in whole the peripheral edge of the light guideplate. Preferably, at least the guide light panel is enclosed. Ofcourse, the backlight module can selectively includes other componentsfor a conventional backlight module such as diffuser films, prism films,or reflectors to enhance or improve the function.

[0012] To illustrate the present invention, exemplary embodiment of abacklight module for flat panel display will now be described withreference to the drawing in which:

[0013]FIG. 1 is a top view of the backlight module according to thepresent invention. The backlight module comprises a light guide plate200 and a frame 300 corresponding to the light guide plate 200. Theperipheral edge of the right and left sides of the light guide plate 200has a projecting lug 220 in the shape of a trapezoid. The projecting lug220 has a top front portion 221 connected to the peripheral edge 212 ofthe light guide plate 200 and a bottom end portion 223 connected to theperipheral edge 214 of the light guide plate 200. The peripheral edge212 of the light guide plate 200 and the other peripheral edge 214 ofthe light guide plate 200 are arranged in a nonlinear manner as viewedfrom the top. Such a nonlinear design can increase the width of thebottom portion of the projecting lug 200. Therefore, the contact areabetween the light guide plate 200 and the frame 300 is enlarged.Accordingly, the impact force is decreased when impact occurs, and also,the possibility of breaking the light guide plate 200 or the lightsource such as CCFL (Cold Cathode Fluorescent Lamp) is reduced. Theprojecting lug 220 is shaped as a trapezoid. The projecting lug 220 hasa slant surface 222 formed at the connection of the top front portion221 thereof and the peripheral edge 212 of the light guide plate. Also,the projecting lug 220 has a bottom surface 224 formed at the connectionof the bottom end portion 223 thereof and the peripheral edge 214 of thelight guide plate, the bottom surface being close to a vertical plane tothe peripheral edge 214 of the light guide plate 200. Further, theprojecting lug 220 has a tip portion 226 at the utmost distance from theperipheral edge 214 of the light guide plate 200. The tip portion 226protrudes beyond the light guide plate 200, but not penetrates throughthe frame 300 corresponding to the light guide plate 200.

[0014] The bottom of the light guide plate 200 may optionally dispose acave 240 corresponding to a lamp holder 410 of a light source 400. Thecave 240 is positioned at the bottom end of the light guide plate 200,and caves in the light guide plate 200 to enclose the lamp holder 410 ofthe light source of the display device without substantially contactingthe lamp holder 410.

[0015] The light guide plate 200 of the present invention can enlargeits contact area with the frame 300 by the projecting lug 220 mounted onthe both sides of the light guide plate 200. According to the principleof σsuch a design can significantly reduce the impact force of the platemodule when impact or any downward movement resulting therefrom exists.The movement of the light guide plate 200 caused by impact will notresult in any crack on the fragile part of the light source (lamp) 400of the display. Furthermore, since the peripheral edge 212 of the lightguide plate 200, connected the top front portion 221 of the projectinglug 220, and the other peripheral edge 214 of the light guide plate 200,connected to the bottom end portion 223 of the projecting lug 220, arearranged in a nonlinear manner as viewed from the top, it increases thedurability of the light guide plate 200 against stress. The projectinglug 220 is disposed on both sides of the light guide platesymmetrically, which will average the impact force when impact of platemodule occurs. Further, the optional design of setting up the cave canreduce the possibility of a direct hit of the light guide plate onto thelight source (lamp), especially to the most fragile part of the lamp(i.e., the lamp holder). This will significantly increase the durabilityto impact for the backlight module of a display and the plate module.

[0016] Although the present invention has been explained in relation toits preferred embodiment, it is to be understood that many otherpossible modifications and variations can be made without departing fromthe spirit and scope of the invention as hereinafter claimed.

What is claimed is:
 1. A backlight module for a flat panel display,comprising: a light guide plate having at least a projecting lug on theperipheral edge of at least one side thereof, said projecting lug beingconnected to a peripheral edge of said light guide plate with a topfront portion thereof and connected to the other peripheral edge on thesame side of the light guide plate with a bottom end portion thereof;and a frame surrounding at least a part of the peripheral edge of saidlight guide plate and including an opening to closely receive saidprojecting lug of said light guide plate; wherein the top front portionof the projecting lug, the bottom end portion of the projecting lug andthe tip portion of the projecting lug at the utmost distance from theperipheral edge on the same side of the light guide plate are disposedin a nonlinear manner among themselves.
 2. The backlight module asclaimed in claim 1, wherein said projecting lug is mounted on one sideof the light guide plate without facing light source.
 3. The backlightmodule as claimed in claim 1, wherein said projecting lugs are mountedon the sides of the light guide plate without facing light sourcesymmetrically.
 4. The backlight module as claimed in claim 1, wherein alight source is provided corresponding to said backlight module, and atleast one side of the light guide plate without facing light sourcehaving a cave to receive a lamp holder of said light source.
 5. Thebacklight module as claimed in claim 1, wherein the peripheral edge ofsaid light guide plate, connected said top front portion of saidprojecting lug, and the other peripheral edge of said light guide plate,connected to said bottom end portion of said projecting lug, arearranged in a nonlinear manner.
 6. The backlight module as claimed inclaim 1, wherein said projecting lug is in a shaped of a trapezoid or atriangle.
 7. The backlight module as claimed in claim 1, furthercomprising a light source.
 8. A light guide plate comprising at least aprojecting lug on the peripheral edge of at least one side thereof, saidprojecting lug being connected to a peripheral edge of the light guideplate with a top front portion thereof and connected to the otherperipheral edge on the same side of the light guide plate with a bottomend portion thereof; wherein the top front portion of the projectinglug, the bottom end portion of the projecting lug and the tip portion ofthe projecting lug at the utmost distance from the peripheral edge onthe same side of the light guide plate are disposed in a nonlinearmanner among themselves.
 9. The light guide plate as claimed in claim 8,wherein a light source is provided corresponding to said backlightmodule, and at least one side of the light guide plate without facinglight source having a cave to receive a lamp holder of said lightsource.
 10. The light guide plate as claimed in claim 1, wherein saidprojecting lug is in a shaped of a trapezoid or a triangle.